Compression keys
The compression key fitted on the crowns of Master
Compressor line watches is a patented system enabling addi-
tional compression of one of the 4 crown gaskets, which
boosts your watch’s long-term water-resistance.
The “open” or “closed” position of the compression key is
indicated by the arrow symbols (viewed from the front):
- The compression key is in the compressed gasket position
(“closed”) if the indicator shows only one arrow; the keys
must be closed when you wear your watch and when you
are taking part in sports. You must not make any adjust-
ments or set the time in this position, since this might
damage the gaskets.
- The compression key is in the non-compressed gasket po-
sition (“open”) if the indication is represented by two ar-
rows; in this configuration, you can start the watch and set
the functions as per the explanations below.
The switch from «closed» to «open» position or vice-versa is
made by turning the key using the wing-nuts in the direction
indicated by the arrow(s).
Note
The water-resistance function of the compression key is sepa-
rate from the operation of the crown itself. Even in the closed
position, the key does not lock the crown. So in practice it is
possible to operate the crown when the key is in the com-
pressed gasket position. However, as mentioned earlier, it is
extremely inadvisable to make adjustments in this position,
since this might damage the gaskets. We recommend that you
first turn the compression key to the “open” position before
making any adjustments to your watch.
Master Compressor Diving, divers’ watches meeting
the NIHS 92-11 (ISO 6425) standards
Master Compressor Diving line watches that bear the title
“diving watches” satisfy the requirements of the Swiss Watch-
making Industry Standard (NIHS) 92-11, reproducing the
European standard ISO 6425.
Warning
As a precaution, we draw your attention to the following two
recommendations:
- You must not operate the crowns in water,
- You must not use Master Compressor Diving watches for
deep dives (diving with a gas mixture, in which the diver
spends alternating periods between the water and a pres-
surised chamber), or at a depth greater than that indicated.
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Technical specifications
- Automatic movement, Calibre 757.
- 28,800 vibrations/hour.
- Power-reserve: approximately 65 hours.
- Crown with compression key.
- Water-resistance: from 30 to 100 atm, according to the
materials.
Movement
Use
Starting the watch
Crown A
Turn the compression key to the “open” position in the direc-
tion of the arrow. Crown A will then be in position 1. A few
clockwise turns of the crown will suffice to start the watch.
It will then automatically wind up when you wear it. Please
note that the crown does not lock on winding, even when
the watch is fully wound.
Once the operation is complete, turn the compression key to
the «closed» position in the direction of the arrows.
Jaeger-LeCoultre Calibre 757
1 2 3
Wing-nuts
Compressed gasket position or
"closed" position
Non-compressed gasket position
or "open" position
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aster
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iving
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- English
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